The present invention relates to oscilloscopes, and more particularly to the use of an analog oscilloscope as a digitizer for converting a repetitive analog signal into a digital signal for storage and/or display.
Analog oscilloscopes are realtime display devices that accept an input signal and display the resulting waveform on a conventional display screen, such as the face of a cathode ray tube (CRT). The major advantage of an analog oscilloscope is that it provides a direct representation of an input signal, and updates at the fastest possible rate since only a beam retrace and trigger rearm are required between sweeps. Digital oscilloscopes on the other hand sample the input signal and convert it into a series of digital words, which digital words may be saved, processed, automatically measured, transmitted to remote locations or output at leisure in hard copy. The digital oscilloscopes sample the input signal using conventional analog-to-digital converters (ADC) that either sample in realtime, i.e., entire waveform in one pass, sample in equivalent time for a repetitive signal to effectively increase the bandwidth by taking several samples per trigger and delaying the trigger per repetition, or provide sequential sampling for repetitive signals with one sample per trigger.
What is desired is a technique using the hardware of an analog oscilloscope to perform a digitizing function on the input signal.